Swiss Law Local Search — MCP Server

Offline full-text search across 35,000+ Swiss laws from all 26 cantons + federal level.

Built on the rcds/swiss_legislation HuggingFace dataset (sourced from LexFind.ch), indexed locally with SQLite FTS5.

Architecture

HuggingFace dataset (35k laws)
        │
        ▼  build_index.py (run once)
   swiss_law.db  (SQLite + FTS5 full-text index)
        │
        ▼  search_client.py
   server.py  (MCP tools)
        │
        ▼  stdio / SSE
   Claude Desktop / Cowork

Setup

cd lexfind-mcp
python3 -m venv .venv
source .venv/bin/activate
pip install -r requirements.txt

# Build the index (downloads ~2-3 GB, takes 5-10 min)
python build_index.py

Add to Claude Desktop

{
  "mcpServers": {
    "swiss-law": {
      "command": "/ABSOLUTE/PATH/TO/lexfind-mcp/.venv/bin/python3",
      "args": ["/ABSOLUTE/PATH/TO/lexfind-mcp/server.py"]
    }
  }
}

Tools

Tool	What	Example
search_laws	Full-text search	search_laws("Raumplanung", canton="zh")
get_law	Metadata by ID	get_law(1234)
get_law_text	Full text	get_law_text(1234)
get_article	Single article	get_article(1234, "22")
list_cantons	Canton overview	list_cantons()

FTS5 query syntax

The search supports SQLite FTS5 syntax:

• Raumplanung — simple term match
• Planungs- und Baugesetz — implicit AND
• "öffentliches Recht" — exact phrase
• title:Baugesetz — search only in title column
• Raumplan* — prefix match
• Baugesetz OR Planungsgesetz — boolean OR
• canton:zh AND Bauordnung — combine with column filter

Combining with the Fedlex MCP

This server and the Fedlex MCP server complement each other:

• This server: fast offline search, covers all cantons, has full text
• Fedlex MCP: live data, amendment history, FRBR versioning, legal taxonomy

You can run both in Claude Desktop simultaneously.

Updating the data

The HuggingFace dataset is a snapshot. To refresh:

python build_index.py   # will ask to rebuild if DB exists

License

Data: CC-BY-SA-4.0 (from HuggingFace dataset) Code: MIT